The present invention relates to a LCD display system, such as an eyewear type viewer, having two liquid crystal display panels.
An eyewear type viewer is a device adapted to be worn over the left and right eyes like a pair of eyeglasses or goggles. The eyewear type viewer may have one LCD panel for both eyes or may have left and right LCD panels for the left and right eyes. Usually, the eyewear type viewer further includes one or more eyepiece lenses through which the eyes view the image or images formed by the LCD panel or panels. The eyewear type viewer is expected to serve as a display system for achieving stereoscopy and virtual reality, or a private video monitor.
Japanese Patent Application (Hei) 3-256836 shows a stereoscopic viewer which utilizes the afterimage effect (or memory effect) of the LCD. This viewer provides a stereoscopic representation by producing a picture for the left eye and a picture for the right eye, transmitted alternately by a video signal, and holds the pictures in the next field. The conventional viewer, however, requires a left drive circuit for driving the left LCD and a right drive circuit for driving the right LCD.
As disclosed in Japanese Patent Application (Shou) 63-331968, there is known a noiseless video representing technique (crystal, clean, still/slow) in a speed change reproduction of a VTR, which utilizes the afterimage effect. In this technique, the video signal produced during the speed change reproduction includes fields with noise, and fields without noise. On the noiseless fields, images are displayed in the normal writing manner. On each field having noise, the image of the most recent noiseless field is held (retained). In this way, the conventional display system achieves the noiseless speed change reproduction. In this case, the image reproducing equipment such as a VTR must supply a write/hold signal for controlling the timing schedules of writing and holding and a quasi vertical synchronizing signal used for the speed change reproduction.
The conventional viewer is disadvantageous, however, specifically in weight and cost because the conventional device requires two of the drive circuits for the left and right LCD panels. Besides, the two separate drive circuits tend to provide an unnatural feeling by producing unbalanced images for the left and right eyes because of a deviation between the output signals of the two drive circuits.
The conventional system further requires two signal lines and terminals for transmitting the write/hold signal and the quasi vertical synchronizing signal. In this point, too, the conventional system is not adequate for weight reduction and cost reduction.